An effect of antiphase boundaries on the kinetics of shortrange ordering by a vacancy mechanism J. Chem. Phys. 88, 3227 (1988); 10.1063/1.453917Effect of thermal relaxation and lowtemperature irradiation on the chemical shortrange order of amorphous ZrFe alloysThe eigenvalues of the g tensor of an irradiation produced defect of the quartz structure have been found to be gl =2.0003, g2=2.0006, g,=2.0018. The data on the center are consistent with the assignment of S=!.Assuming that the hyperfine interaction with Si 29 (I=! and 4.7% abundant) is negligible, the envelope of the line is calculated for 4 widths of the line. Good agreement is found between the calculated envelope for a width of 0.2 oe and the envelope observed in 'Y-ray and in neutron-irradiated (~10 18 fast neutrons/cm') silica. The observed envelope deviates from the calculated envelope for increasing neutron irradiation. It is suggested that a correlation of the Si-O tetrahedra, similar to a-quartz, exists around any point in the more common forms of silicas and has a diameter of 25 A.
The correlation of two paramagnetic defects, observed by the electron spin resonance (ESR) technique, with two optical absorption bands produced by r‐ray or neutron irradiation is indicated. The peaks of the two absorption bards fall at ∼2100 8.u. and 2300 a.u. The effective g values for the ESR lines, for a crystal orientation with respect to the magnetic field of 100.1] parallel to H2, are 2.0006 plusmn; 0.0005 for the 2100 a.u. band, and there are two lines observed for the 2300 a.u. band at [g= 2.0007 and g= 2.00091 ± 0.0005. The correlation of the optical bands and ESR lines was established by a series of bleaching and annealing experiments. These experiments also establish the presence of another center which is not observed directly by either the optical or the ESR technique. ESR lines were observed which were attributed to a hyperfine interaction, A= 7.7 oersteds, of the g= 2.0006 (2100 a.u. band) defect with the Si29 isotope (I = 1/2, 4.7% abundance). Models for these defects, consistent with the experimental data, are suggested.
Thermal GeO2 oxides up to 136 nm thickness were produced by annealing Ge wafers in pure oxygen at 550 °C and 270 kPa pressure for up to 10 h. The oxidation kinetics followed the Deal–Grove law. Using multisample spectroscopic ellipsometry for a series of five thermal oxides with different thicknesses, the complex dielectric functions of Ge and GeO2 were determined from 0.5 to 6.6 eV, for thin-film metrology applications in Ge-based microelectronics and photonics. The dispersion of the GeO2 layer was modeled with a simple Tauc-Lorentz oscillator model, but a more complicated dispersion with eight parametric oscillators was required for Ge. A reasonable fit to the ellipsometric angles could be obtained by assuming that all thermal oxides can be described by the same dielectric function, regardless of thickness, but a slight improvement was achieved by allowing for a lower density oxide near the surface of the thickest films. The authors compare their results with literature data for Ge and bulk and thin-film GeO2.
Evidence is given for the correlation between an optical absorption band at 2300 a.u. and an electron spin resonance system developed in quartz after 6oCo y-irradiation. The results of bleaching 7-irradiated quartz and silica at 78°K. and at room temperature are presented and discussed. Also, further observations upon annealing these color centers are given.
Using Fourier-transform infrared spectroscopic ellipsometry, the infrared lattice absorption of LiF and NiO was studied in the reststrahlen region. The transverse optical (TO) and longitudinal optical phonon energies, broadenings, and amplitudes were determined. Both materials also show a weak two-phonon absorption, which modifies the shape of the reststrahlen bands. The authors did not find any evidence of a splitting of the TO phonon in NiO due to antiferromagnetic ordering and place an upper limit of 17 cm À1 on this splitting. V
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.